High quality single crystals, such as aluminum nitride or zinc oxide, are produced using various high temperature crystal growth techniques. Many of these growth techniques involve heating reactants used to form the crystals at high temperatures for extended time periods. As such, the materials used to construct high-temperature components such as furnace or crucible walls in the reactors used for high temperature crystal growth may be subjected to temperatures in excess of 2000° C. in the presence of reactive gases or plasma. Desired characteristics for these materials may include resistance to outgassing, sublimation, or chemical reactions with crystal growth reactants at high temperatures, ease of fabrication into a variety of shapes, and economic viability for mass production. The materials used in the fabrication of existing high-temperature components may typically possess only one or two of these desired characteristics.
Some materials that may be resistant to chemical attack at elevated temperatures may also be difficult and expensive to machine or shape. For example, tantalum carbide (TaC) is extremely resistant to chemical attack at elevated temperatures and may be produced using two different methods. TaC may be produced from Ta metal by a direct carbonization process, but the relatively low diffusivity of carbon reactants through the tantalum metal produces only a surface coating of TaC. In order to achieve the full conversion of a Ta structure to TaC by direct carbonization, a process time on the order of weeks may be necessary. A TaC component fabricated as a sintered-pressed TaC powder reduces the fabrication costs, but the possible shapes produced by the powder sintering are inherently limited by the process. In addition to fabrication costs, tantalum is relatively expensive compared to tungsten or other high-temperature materials.
There exists a need for an economical method of producing high-temperature components, such as furnace or crucible walls, using affordable materials that are highly resistant to degradation or other chemical reactions at high temperatures. In particular, a need exists in the art for a method of producing high-temperature components by converting a component formed from a relatively easily machined or shaped refractory metal material into a high-temperature component by reacting the refractory metal with one or more reactive gases to form a non-reactive, refractory metal compound that is stable at high temperatures.